Centrifugal pump



Jan. 3, 1928.

A. B. WOOD CENTRIFUGAL PUMP Filed sept. s, 1925 INVENTOR wat f5. M

A TTORNEYS .Patented dan. E3, '1928.

raiser .ALBERT B. WOOD, OF NEW ORLEANS, LOUISIANA.

CENTRIIE'UGAL PUMP.

Application led September 5, 1925. Serial No. 54,595.

This invention relates to the balancing of pump inipellers and isparticularly useful in connection with centrifugal pumps,

@ne of the primary objects of my invention is to balance the pump in animproved,

simple-and edective manner.

Other objects and advantages will appear' hereinafter in thespecification of the preferred form of my invention illustrated in lothe accompanying drawings, wherein:

Fig. 1 is across section of the pump and Fig. 2 is a plan section of the-pump impeller vtaken-on the line 2-2 of Fig. 1.

Referring now to the drawings it will be l5 seen that the pump comprisesin general a pump casing A, an impeller and an impeller shaft C, havingits bearing at 7 1n the pump casing A.'

A central inlet opening 8 is provided in the casing which constitutesthe .suction inlet of the pump, thru which fluid is drawn by theimpeller'and delivered to the circumferential discharge or volute 9 ofthe casing.

For conveniencein manufacture and as# sembling the pump casing A is madeof several parts in this instance an inlet member 8a, an outlet member9a, and a bearing member 7a.

rIlie impeller B is an enclosed impeller that is to say it consists oftwo walls or discs 10 and 11 spaced apart and connectedby a plurality ofimpeller blades lor vanes 12. 12 iii this instance two being shown.

rEhe fluid enters the impeller at 13 andis impelled by the blades 12, 12into the circumferential discharge 9. The blades or vanes 12, 12 extendfrom a point. 14 adJacent the uid entrance 13 `to a point 15 on thecircumference of the impeller, said blades diminishing from aconsiderable thickness at 14 to but little at the periphery at 15 andbeing suitably curved to efectively impel the duid and foreign substancethrough the pump with increasing velocity as it enters the chamber oroutlet 9. It will be seen that the inner edges 16 of the blades 12, 12are rounded as are the points of con-.

nection to the walis or discs 10 and 11 thus preventing to a greatextent the lodging of' foreign substances at these points.

It is further pointed out that the passages 17, 1'? thru which the fluidis impelled increase in width toward the circumference of theimpeiler,'the minimum width approximating the size of the fluid entrance13.

This further prevents lodgment of foreign substances in the pump and thepump will pass anything that will enter the inlet, making it very usefulfor draining swamps andH the like.

Owing to the clearances between the pump impeller B and the casing A atthe points 18, 19 and 20, Huid leaks past these points into theclearance spaces 21 and 22 which without provision to the contrary wouldcause unbalanced strains on the impeller in van axial direction becauseof different pressure conditions in the spaces 21 and 22. In order toprevent such unbalancing I have provided the passages 23, 23 extendingthru the discs 10 and 11and blades 12, 12 whereby the fluid on eitherside of theimpeller is in communication thus equalizing the` pressureand consequently balancing the impeller.

It will be seen that by this arrangement the pressure on the discs 10and 11 is equa1- ized without wasting fluid or requiring its repumpage,thus improving the eiiiciency of the pump; The life of the pump is alsomaterially increased because the amount of fluid and foreign substanceentering the space v21 through v`the clearance point 18 is very muchreduced whereby the consequent wear at the point 18 on the disc 10 andthe part 7a is much reduced.

Itis to be observed that by employing impeller blades constructed inaccordance with my invention I am enabled to conveniently locate thebalancing passages 23, 23 in the thick portion of the blades, thusavoiding the necessity of providing bridges from disc to disc for saidpassages which would defeat. the general purpose of this pump which isto combine eiiiciency with ability to pass anything which will enter theinlet.

In some instances it may well be that a single balancing passage 23would suiiice.

1. In a pump, the combination of a casing having a central inlet andcircumferential outlet, an limpeller within the casing comprisingAspaced discs and a plurality of impeller blades connecting said discs, apump shaft on the end of which the impeller is carried whereby the inletis unobstructed, there being a spacenbetween each end face oftheimpeller and the casing, clearance spaces between the impelier andthe casing communicating with said end `spaces whereby impelled fluidenters said end spaces, and a port extending through a blade andConnecting said end spaces, said port being located at the inner end ofthe blade and close to the inlet. A

2. In a pump, the combination of a casing having a central inlet andcircumferential outlet, an impeller within the casing comprising spaceddiscs and a plurality of impeller blades connecting said discs, a pumpshaft on the end of which the impeller is carried whereby the inlet isunobstructed, the passages formed by the blades being of such size 'aswill pass anything which will enter the inlet, there being a spacebetween each end face of the impeller and the casing, and clearancespaces between the impeller and the casing communicating with said endspaces whereby impelled fluids enters the end spaces, and a ortextending through a blade and connecting said end spaces, said portybeing in close proximity to the entrance edge of the blade.

vided with forward ends whichl are thick.

and rounded andwwith rear ends occupying but little of the periphei ofthe im eller,

a shaft on theend of whlch the'impe ler'is" carried whereby the inlet isunobstructed, a space between each end face of the impeller and thecasing, clearance spaces between the impeller and the casingcommunicating with the end spaces whereby impelled liuid enters` thelatter, and a port extendin through the thick end of each blade insustantiallparallelism 'with the axis of the shaft and connectin'g theend spaces.

In testimony whereof, I have hereunto signed my name.

' ALBERT B. WOOD.

